#!/usr/bin/env python3

import numpy as np
import cv2 as cv

# def draw_circle(event,x,y,flags, param):
#     if event == cv.EVENT_LBUTTONDBLCLK:
#         cv.circle(img,(x,y),100,(255,0,0),5)

drawing = False  # 如果按下鼠标，则为真
mode = True  # 如果为真，绘制矩形
ix, iy = -1, -1


# 鼠标回调函数
def draw_circle(event, x, y, flags, param):
    # print(event)
    global ix, iy, drawing, mode
    if event == cv.EVENT_LBUTTONDOWN:
        drawing = True
        ix, iy = x, y
    elif event == cv.EVENT_MOUSEMOVE:
        if drawing == True:
            if mode == True:
                cv.rectangle(img, (ix, iy), (x, y), (0, 255, 0), 1)
            else:
                cv.circle(img, (x, y), 50, (0, 0, 255), 1)
    elif event == cv.EVENT_LBUTTONUP:
        drawing = False
        if mode == True:
            cv.rectangle(img, (ix, iy), (x, y), (0, 255, 0), 1)
        else:
            cv.circle(img, (x, y), 50, (0, 0, 255), -1)
    elif event == cv.EVENT_RBUTTONDOWN:
        mode = not mode


img = np.zeros((512, 512, 3), np.uint8)

cv.namedWindow("image", cv.WINDOW_NORMAL)
cv.setMouseCallback('image', draw_circle)

while True:
    cv.imshow('image', img)
    if cv.waitKey(20) & 0XFF == 27:
        break

cv.destroyAllWindows()
